Probably the most common problem with submitted files is that they tend to be low in resolution and in edge clarity. The reason this is a concern for images that will be broken into halftones is that without a clear definition to the edges in an image, the ink tends to wander past where it should go and the whole graphic can begin to look fuzzy or indistinct. A lot of times this is something that won’t be caught until it is being printed as well, because the computer simulation will show a clear edge to graphics. This is because it doesn’t simulate the degrading of the halftones on the edges and the tendency for low end dots to become lost in the screen making process.

Remember, a 5% dot on the computer screen that creates an edge in a dark garment will likely not hold on the screen unless you use a very controlled process. Most printers are lucky to hold 10% dots in, especially with film. In the example image (Figure 1) the digital picture looks fine from a distance, but on closer inspection the edge quality is poor. The likely result of this is that the fur texture and eye would mash together in the final print and cause a very muddy appearance.

The solution for this issue is to carefully check the density of your edge defining areas in the image and to make adjustments for areas that are too low and will probably be squeezed out in the screen creation process. A filter in Photoshop can aid this process, so I took the wolf image and created a duplicate layer of the wolf, used the Curves menu to increase the contrast of the image slightly (deepened the blacks and brightened the whites), and then ran the Poster Edges filter on a light setting of 1 edge thickness, 0 edge intensity, and 6 on posterization.